The invention relates to a method and arrangement for coating orifice walls, and more particularly to a method of coating the inner walls of at least one orifice of a perforated plate or board with a liquid.
Such a method is used in particular in so called raster orifice plates or boards in which, for example, inner walls of a certain number of orifices are to be coated with the same or a different material. It is important for some applications that only the inner walls of the orifices should be coated whereas the remaining parts of the raster orifice board are to remain uncoated.
German patent application No. P 30 33 962, which is not a prior publication, discloses a chemical process in which raster orifice plates or boards are treated with different liquid substances such that only the inner walls of the orifice are coated and multi-coloured coating is possible because of the use of masks, these masks preferably being in the form of self-adhesive films.
This type of masking process generally takes up a lot of material and/or time.